1. Field of the Invention
The present invention relates to a spring seat and a damper disk assembly, and more particularly relates to a spring seat that supports a spring that absorbs and dampens torsional vibration.
2. Background Information
To transmit the power generated by an engine, a vehicle is equipped with power transmission devices such as a clutch disk assembly, a flywheel assembly, and a torque converter lock-up apparatus. These power transmission devices are provided with a damper disk assembly that absorbs and dampens torsional vibrations and the like.
This kind of damper disk assembly main includes an input rotor, an output rotor, and a plurality of coil springs. The coil springs are disposed in a window or windows formed in the output rotor. When the input and output rotors rotate relative to each other, the coil springs are compressed in the rotational direction between the two rotors, which causes the torsional vibration inputted to the input rotor to be absorbed and dampened.
However, since the coil springs are subjected to centrifugal force, when they are compressed they move to the outside in the radial direction. As a result, the coil springs slide over the support components, for example, and strong frictional resistance is generated between the coil springs and the input rotor. This frictional resistance diminishes the ability of the damper disk assembly to dampen torsional vibration.
In view of this, a pair of spring seats were mounted at the ends of the coil springs in a conventional damper disk assembly (see Japanese Laid-Open Patent Application 2004-183871, for example). The spring seats can be made from plastic, metal, or another material, for example.
The spring seat discussed in Japanese Laid-Open Patent Application 2004-183871 has a sliding component disposed on the outside of the coil springs in the radial direction. The sliding component supports the ends of the coil springs in the radial direction. This prevents the coil springs from sliding over the support component.
If a spring seat has relatively low stiffness, however, when the coil springs are subjected to a strong centrifugal force, the sliding component is subjected to a large load to the outside in the radial direction, and the sliding component elastically deforms to the outside in the radial direction. As a result, for example, the sliding component slides over the support component, and frictional resistance is generated between the spring seats and the input rotor. This frictional resistance can bring about a decrease in the ability of the damper disk assembly to dampen torsional vibration. That is, if the stiffness of the spring seats is low, there is the risk that the ability of the damper disk assembly to dampen torsional vibration will be diminished.
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved spring seat and damper disk assembly. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.